JUDY WOODRUFF: Now a coming crisis in the classroom, as more teachers exit the profession. A nonprofit organization is combating the high turnover rates by mentoring new teachers.

Our story comes from Ash-har Quraishi of WTTW Chicago.

ABBY MILLER, Sumner Elementary School: Eyes up on the board. Let's read our question real quick.

ASH-HAR QURAISHI:Walk in to Abby Miller's third grade class at Sumner Elementary School on Chicago's West Side and you would never guess this is her first year teaching.

ABBY MILLER:If he puts them in 10 rows, how many chairs should he put in each row? Get to work. I'm setting the timer for six minutes.

ASH-HAR QURAISHI:She exudes the confidence and authority of an old hand in front of her sometimes unruly 8-year-old students.

ABBY MILLER:My mom and I have this running joke that in my first year of teaching, I actually have 15 years of experience.

ASH-HAR QURAISHI:Still, it's been a tough year for Miller and for the Chicago Public School District as a whole.

PROTESTER: Whose choice was this?

PROTESTERS: Rahm's choice!

ASH-HAR QURAISHI:The year began with a bitter dispute between the Chicago teachers union and Mayor Rahm Emanuel over wages, teacher evaluations and class size. It was the district's first strike in 25 years.

And then the city's controversial decision to close more than 50 elementary schools sparked renewed opposition from teachers. The closings this fall will be the nation's largest ever.

Amidst all the very public disruptions, about 100 Chicago public schools suffer from chronically high rates of teacher turnover, losing a quarter or more of their teaching staff every year.

As a result, there are thousands of new teachers, like Abby Miller, who are trying to take charge of a classroom for the first time.

ABBY MILLER:How come every time we come back from math lab, half the class has lost their pencil?

ASH-HAR QURAISHI:To say it's a challenge is an understatement.

ABBY MILLER:I think I kind of had a false sense of what I was getting myself into. You can study it in a classroom. You can say, oh, well, if this student does this, then you should do this, if this student does that, you should do that, but really it depends on where you teach, it depends on who you teach.

Things that worked for my fifth graders at the beginning of the year don't work over here. Things that work over here with the third graders didn't work with my fifth graders. And I have a strong feeling that things that worked this year are not going to work next year.

ASH-HAR QURAISHI:Her experience of trial by fire in the classroom is increasingly common. A recent national study found that the teaching work force is getting younger and less experienced. Making matters worse is a tsunami of retiring veteran teachers. Between 2004 and 2008, more than 300,000 veteran teachers left the work force for retirement.

Walk into any classroom in the country today and you're more likely to find a teacher in their first year of teaching than any other experience level. And they're not sticking around.

At the core of the crisis, the experts say, that first-year teachers are particularly vulnerable when it comes to buckling under the pressures and frustrations they are sometimes ill-prepared to face once they take to the classroom.

ELLEN MOIR, University of California, Santa Cruz: It's a huge problem. I mean, we lose 50 percent of all new teachers in the first three to five years.

ASH-HAR QURAISHI:Ellen Moir saw the problem firsthand. As a director of teacher education at the University of California, Santa Cruz, she found that success was eluding even her best and brightest student teachers.

ELLEN MOIR:They said, oh, my gosh, I thought I was going to be a great teacher, and I'm really -- I'm not. And I feel like a fraud. I shouldn't really be doing this work. And I thought, wait a minute, there's some disconnect here if you could really get a great teacher ed program and you tee someone up for their first year of teaching. What's the problem?

ASH-HAR QURAISHI:Inevitably, she says, these teachers faced some of the toughest assignments in some of the country's toughest schools, and they were left to sink or swim.

To combat that, she founded the New Teacher Center, a nonprofit educational organization that focuses on first-year teacher mentoring and development led by skilled veteran teachers.

LARISSA BENNETT, New Teacher Center: Tell me about some of the things that have been a challenge or concern for you lately.

ASH-HAR QURAISHI:Larissa Bennett is one of those expert teachers and has been mentoring Abby Miller for the better part of the last school year. Mentors like Bennett meet one-on-one with their apprentices to provide professional development, leadership training, and specific advice on classroom management.

ABBY MILLER:They did just below what I expected and it was hard not to see that as like a reflection upon my teaching. So, that was a tough day.

LARISSA BENNETT: We want them to know that they have someone that they can go to. Teachers that feel supported, that feel appreciated and valued stay in the profession. So if we can get to those teachers their first year and make them feel those things, give them the tools to succeed, they will stay.

ASH-HAR QURAISHI:In addition to that support, Bennett says teachers in big districts like Chicago don't have the luxury of taking months and years to become effective.

LARISSA BENNETT: We need them great yesterday. So we help them develop skills and strategies to teach in these difficult areas.

ASH-HAR QURAISHI:The high dropout rate for new teachers is also expensive. For example, the price tag associated with recruiting, hiring, and training replacement teachers is substantial. It's estimated that every time a teacher walks out the door in Chicago, it costs the district about $18,000 to replace them.

According to a report from the National Commission on Teaching and America's Future, the total cost of turnover in the Chicago public schools is estimated to be over $86 million a year. Nationally, that figure tops more than $7 billion annually.

WOMAN: And you want to make sure you're asking those mentoring questions, right? You know, I'm wondering have you thought about doing it this way? You know, could it be possible that? Thinking about where the teacher is in their practice.

ASH-HAR QURAISHI:New Teacher Center mentors meet regularly with other expert teachers to discuss protocols for supporting their first-year teachers. They partner with school districts and educators to help implement best practices for new teacher induction.

ELLEN MOIR: As the country's talking about developing teachers, I think there's a much greater understanding and recognition that really talented teachers are not born. They're made. And we have to be systematic about it and we need to really build off of the talent that we have in our school systems.

ASH-HAR QURAISHI:The New Teacher Center has financial support from numerous foundations, as well as the U.S. Department of Education. It's one of the largest teacher mentoring resources in the nation. Today, the organization reaches over 15,000 new teachers, in all 50 states, with about 7,000 expert teachers, and is being modeled in countries like Singapore, Finland, Scotland, and Panama. And Moir says it's working.

ELLEN MOIR: It's a great idea and it's super successful. I mean, look, it's hard to measure teacher effectiveness, but let me talk a little bit about the retention side of the equation. We're easily upping retention by 20 percent in the districts that we're working in. In the 24 largest -- 24 of the largest urban districts, I mean, retention is up significantly.

ASH-HAR QURAISHI:And for teachers like Abby Miller, while this year has tested her resolve, she says the mentoring has helped her retain the grit that got her into teaching in the first place.

ABBY MILLER:Right now, I see myself still teaching. I -- there is a reason that I decided to come into teaching. There's a reason that I decided to leave the career I had before and make this switch. And it's tough.

There are days where I come home and throw up my arms and say, I'm done, I'm not doing it anymore, but those are in the rarity. And there are more days when I come home and say, I helped this kid learn this today.

ASH-HAR QURAISHI:Using a grant from the U.S. Department of Education, the New Teacher Center plans to expand in Chicago with a focus on high-poverty schools.